Laser Cutting Equipment

Abstract

An apparatus for laser cutting a secondary battery material according to one embodiment of the present invention includes a first laser light source that emits a first laser for cutting the secondary battery material and a second laser light source that emits a second laser for heating the portion of the material to be cut, and the first laser and the second laser are irradiated onto the material in a synchronized state.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0038716, filed on March 24, 2023, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a cutting device using a laser, and more specifically to a laser cutting device that cleanly processes the cut area in a process of cutting secondary battery materials using a laser, thereby further improving the quality of the cut material. [Background technology]

[0003] In modern society, as the use of portable devices such as mobile phones, laptops, video cameras, and digital cameras has become commonplace, there has been active development of technologies related to these mobile devices. Furthermore, rechargeable secondary batteries are being used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and other vehicles as a measure to address air pollution caused by existing gasoline-powered vehicles that use fossil fuels, and as such, there is an increasing need for development of secondary batteries.

[0004] Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are attracting attention because they have the advantages of almost no memory effect compared to nickel-based secondary batteries, free charging and discharging, a very low self-discharge rate, and high energy density.

[0005] The manufacturing process for such lithium secondary batteries is broadly divided into three stages: the electrode process, the assembly process, and the chemical formation process. The electrode process is further divided into the active material mixing process, the electrode coating process, the rolling process, the slitting process, and the winding process. For example, when cutting the electrodes in the slitting process, a press machine with a blade is sometimes used, but lasers are also used to cut the electrodes as much as possible to minimize the occurrence of foreign matter and breakage.

[0006] FIG. 1 shows a laser cutting device according to the prior art. The laser cutting device includes a laser light source 11 that irradiates a secondary battery material 1, such as an electrode sheet, with a laser, and may include a mirror (not shown) and / or a lens 12 on the light path so that the laser light path can be changed and adjusted. According to such prior art, the laser light source 11 irradiates an infrared laser. The pulse duration of the laser is, for example, picoseconds (ps, 10 -12 s) units.

[0007] When cutting secondary battery materials 1 such as electrode sheets using such a laser cutting device, more effective measures are required to cleanly process the cut areas. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a laser cutting device that has improved quality by neatly processing the cut area in the process of cutting secondary battery materials using a laser.

[0009] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0010] An apparatus for laser cutting a secondary battery material according to one embodiment of the present invention includes a first laser light source that emits a first laser for cutting the secondary battery material and a second laser light source that emits a second laser for heating the portion of the material to be cut, and the first laser and the second laser can be irradiated onto the material in a synchronized state.

[0011] The second laser heats the material, thereby increasing its reactivity and removing by-products generated by the cutting.

[0012] The first laser may have an ultraviolet band and the second laser may have an infrared band, and the output power of the second laser may be less than the output power of the first laser.

[0013] The duration of the pulse of the second laser may be longer than the duration of the pulse of the first laser.

[0014] The duration of the pulse of the first laser is from a few picoseconds to a few thousand picoseconds (ps, 10 -12 s) or a few femtoseconds to thousands of femtoseconds (fs, 10 -15 s), and the duration of the pulse of the second laser is from a few nanoseconds to thousands of nanoseconds (ns, 10 -9 s).

[0015] The first laser and the second laser may be coaxially irradiated onto the material, and the beam width of the second laser may be larger than the beam width of the first laser.

[0016] The laser light source may further include a pulse synchronization unit coupled to the first laser light source and the second laser light source, respectively, and the pulse synchronization unit may synchronize the first laser and the second laser emitted from the first laser light source and the second laser light source, respectively, to perform pulse width modulation (PWM).

[0017] The laser includes an optical splitter that combines the first laser and the second laser emitted from the first laser light source and the second laser light source, respectively, on one optical path, and the combined first laser and second laser can be irradiated onto the material.

[0018] The optical splitter can reflect the first laser and transmit the second laser.

[0019] The angle between the first laser entering the optical splitter and the first laser exiting the optical splitter may be 90 degrees, and the angle between the second laser entering the optical splitter and the second laser exiting the optical splitter may be 180 degrees.

[0020] The optical splitter may be a planar optical splitter or a cube optical splitter.

[0021] The planar optical splitter may be a mirror that reflects the first laser and transmits the second laser.

[0022] The laser beam source further includes a focusing lens disposed in an optical path between the optical splitter and the material, and the focusing lens can converge the first laser and the second laser and focus and irradiate the material.

[0023] The focusing lens may be at least one, and may include a planar convex lens, a double-convex lens, or a meniscus convex lens.

[0024] The second laser may further include an aperture for adjusting a beam width of the second laser.

[0025] The optical fiber further includes a mirror disposed between the first laser light source and the optical splitter, and the mirror can adjust the optical path of the first laser incident on the optical splitter.

[0026] further comprising a mirror disposed between the second laser light source and the optical splitter; The mirror can adjust the optical path of the second laser incident on the optical splitter.

[0027] The secondary battery material may include at least one of a positive electrode, a negative electrode, and a separator of a secondary battery. [Effects of the Invention]

[0028] According to the embodiment of the present invention, there is an advantage that the cutting portion (such as the boundary portion of the cutting surface) can be neatly treated in the cutting process of the secondary battery material.

[0029] Furthermore, by using the laser cutting device according to an embodiment of the present invention, the quality of the electrodes and / or separators manufactured thereby can be significantly improved, thereby improving the performance of the batteries manufactured thereby. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a diagram illustrating a laser cutting device according to the prior art; [Figure 2] 1 is a diagram illustrating a schematic diagram of a laser cutting device according to an embodiment of the present invention. [Figure 3] FIG. 3 is a partially enlarged view of the laser cutting device of FIG. 2. [Figure 4] 3 is a diagram showing a case where pulses from a first laser and a second laser of the laser cutting device of FIG. 2 are provided in synchronization with each other. [Figure 5] FIG. 10 is a diagram schematically illustrating a laser cutting device according to another embodiment of the present invention. [Figure 6] 10 is a diagram schematically illustrating a laser cutting device according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031]

[0033] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the embodiments. The present invention may be embodied in various different forms other than those described below, and the scope of the present invention is not limited to the embodiments described herein.

[0032] In order to clearly explain the present invention, parts unnecessary for the explanation have been omitted and the same reference numerals have been used throughout the specification to refer to the same or similar components.

[0033] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily enlarged or reduced for the convenience of explanation, and it is obvious that the contents of the present invention are not limited to those shown. In the following drawings, the thickness of each layer is enlarged to clearly show multiple layers and regions. In the following drawings, the thickness of some layers and regions is exaggerated for the convenience of explanation.

[0034] Furthermore, when a layer, film, region, plate, etc. is described as being "above" another portion, this should be interpreted as including not only the case where the layer, film, region, plate, etc. is "directly above" the other portion, but also the case where there is another portion between them. Conversely, when a layer, film, region, plate, etc. is described as being "directly above" another portion, it means that there is no other portion between them. Furthermore, being "above" a reference portion means being located above or below the reference portion, and does not necessarily mean being "above" in the opposite direction of gravity. Meanwhile, descriptions of being "above" another portion, as well as descriptions of being "below" another portion, should be understood with reference to the above content.

[0035] Furthermore, since the upper and lower surfaces of a particular component can be determined differently depending on the reference direction, throughout this specification, "upper surface" or "lower surface" is defined to mean the two surfaces of the component that face each other along the z-axis.

[0036] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements and may further include other elements, unless specifically stated to the contrary.

[0037] Furthermore, throughout the specification, the term "on a plane" means when the part in question is viewed from above, and the term "in cross section" means when the part in question is cut vertically and viewed from the side.

[0038] Hereinafter, a laser cutting device according to an embodiment of the present invention will be described.

[0039] Fig. 2 is a schematic diagram of a laser cutting apparatus 100 according to one embodiment of the present invention. Fig. 3 is a partially enlarged view of the laser cutting apparatus 100 of Fig. 2. Fig. 4 shows a case where the pulses of the first laser A and the second laser B of the laser cutting apparatus 100 of Fig. 2 are provided synchronized with each other.

[0040] A laser cutting apparatus 100 according to one embodiment of the present invention includes at least two laser light sources having wavelengths in different bands. Figure 2 shows an embodiment of the present invention in which the laser cutting apparatus 100 includes a first laser light source 110 and a second laser light source 120.

[0041] First, the secondary battery material 1 that can be cut by the material cutting device according to an embodiment of the present invention may be, for example, an electrode sheet and / or a separator sheet. The electrode according to the present invention may be a positive electrode or a negative electrode. That is, the material cutting device according to an embodiment of the present invention is not particularly limited to positive electrodes and negative electrodes, but can be easily applied to cutting any electrode, and different electrodes can be manufactured depending on the material (e.g., positive electrode active material or negative electrode active material) used to manufacture each electrode. Similarly, the material cutting device according to an embodiment of the present invention is not particularly limited to the type of separator (type based on components, materials, etc.), and can be easily applied to cutting any separator. Furthermore, the material cutting device according to an embodiment of the present invention is not limited to the above-mentioned materials, but can be applied to a variety of materials used in manufacturing secondary batteries.

[0042] The first laser light source 110 emits a first laser A for cutting the secondary battery material 1. The first laser light source 110 emits, for example, a first laser A in the ultraviolet band. The pulse duration of the first laser A is, for example, picoseconds (ps, 10 -12 s) or femtoseconds (fs, 10 -15 That is, the duration of the pulse of the first laser A can be in the order of a few picoseconds to thousands of picoseconds (ps, 10 -12 s) or a few femtoseconds to thousands of femtoseconds (fs, 10 -15 s).

[0043] For reference, a femtosecond laser refers to a laser with an extremely short pulse width (duration) of femtoseconds, and a picosecond laser refers to a laser with an extremely short pulse width (duration) of picoseconds. When the short pulse width and high peak power characteristics of a femtosecond or picosecond laser are used for laser processing, the duration of the irradiated laser pulse is shorter than the thermal diffusion time of the processing material, enabling non-thermal processing without thermal denaturation of the material.

[0044] Furthermore, when using such femtosecond or picosecond lasers, they can produce a large peak output with relatively less energy than existing continuous wave or nanosecond lasers, which reduces the impact on the processed sample and enables high-quality ultra-precision micromachining.

[0045] The second laser light source 120 emits a second laser B to heat the portion of the secondary battery material 1 to be cut (cut portion). The second laser B is synchronized with the first laser A as described below, and is irradiated onto the material 1 with a single optical path (see FIG. 4). Heating the material 1 with the second laser B improves its reactivity (electronic reactivity, etc.). In addition, by-products generated during cutting with the first laser A are removed by reacting with the second laser B, resulting in a clean cut portion of the material 1.

[0046] The second laser light source 120 emits, for example, a second laser B in the infrared band. Since the second laser B heats the portion of the material 1 where the material 1 is to be cut, the second laser light source 120 has a lower output than the first laser light source 110 that emits the first laser A, which is a cutting laser. In addition, the pulse duration of the second laser B is, for example, nanoseconds (ns, 10 -9 That is, the duration of the second laser B pulse can be in the order of a few nanoseconds to thousands of nanoseconds (ns, 10 -9 s).

[0047] Meanwhile, in one embodiment of the present invention, the first laser light source 110 and the second laser light source 120 are each connected to a pulse synchronization unit 130. The pulse synchronization unit 130 delays and synchronizes the first laser A and the second laser B emitted from the first laser light source 110 and the second laser light source 120, respectively, and then inputs a pulse width modulation (PWM) signal to each of the first laser A and the second laser B. That is, an external trigger signal is input to each of the first laser A and the second laser B, causing the first laser A and the second laser B to emit in the form of a PWM signal. As a result, as shown in FIG. 4, synchronized first laser A and second laser B pulses can be obtained.

[0048] When such pulse-synchronized first laser A and second laser B are irradiated onto material 1, first laser A cuts material 1, and the by-products of cutting material 1 are heated and removed by second laser B, thereby improving the quality of the cut material 1.

[0049] Meanwhile, as described above, it is necessary to unify the optical paths of the first laser A and the second laser B so that the first laser A and the second laser B are emitted in synchronization and can be irradiated onto the same portion of the material 1. The laser cutting device 100 according to one embodiment of the present invention includes an optical splitter 140 disposed on an optical path leading from the first laser light source 110 and the second laser light source 120 to a focusing lens 150, which will be described later.

[0050] The optical splitter 140 combines the first laser A and the second laser B emitted from the first laser light source 110 and the second laser light source 120, respectively, onto a single optical path. The combined first laser A and second laser B are irradiated onto the material 1.

[0051] The optical splitter 140, for example, reflects a first laser A for cutting the material 1 and transmits a second laser B for heating the portion of the material 1 to be cut. FIG. 2 shows a case where a flat optical splitter 140 is included. For example, the optical splitter 140 can be implemented as a mirror, and depending on the degree of coating on the reflective surface, the first laser A can be reflected and the second laser B having a different wavelength band can be transmitted. As a result, as shown in FIG. 3, the first laser A and the second laser B can be irradiated onto the same portion of the material 1 (the portion to be cut).

[0052] First, in order for the second laser B to pass through the optical splitter 140, the angle between the path of the second laser B entering the optical splitter 140 and the path of the second laser B exiting from the optical splitter 140 is 180 degrees (i.e., a straight line). On the other hand, in order for the first laser A to be reflected by the optical splitter 140 while unifying its optical path with the second laser B, the angle between the path of the first laser A entering the optical splitter 140 and the path of the first laser A exiting from the optical splitter 140 is 90 degrees (i.e., a right angle).

[0053] Furthermore, the laser cutting apparatus 100 according to one embodiment of the present invention includes a focusing lens 150. The focusing lens 150 can be disposed in the optical path between the optical splitter 140 and the material 1. The focusing lens 150 enables the first laser A and the second laser B, whose optical paths are combined by the optical splitter 140, to be focused and irradiated onto the material 1.

[0054] The focusing lens 150 focuses the first laser light source 110 and the second laser light source 120 and the first laser A and the second laser B emitted therefrom, respectively, and irradiates them onto the material 1. The focal length and size (shape) of the first laser A and the second laser B, whose optical paths are combined, on the material 1 can be adjusted by the focusing lens 150. In other words, the focusing lens 150 can not only adjust the light width of the first laser A and the second laser B irradiated onto the material 1, but also adjust the height of the laser spot, which has passed through the focusing lens 150 and been focused, relative to the material 1.

[0055] 2, the focusing lens 150 may be a planar-convex lens having one convex surface and the other planar surface, but the present invention is not limited to the illustrated example and various modifications and variations are possible, such as a double-convex lens having convex surfaces on both sides or a meniscus convex lens having one convex surface and the other concave surface. The focusing lens 150 may be a single lens as shown in FIG. 2, but various combinations are possible, such as a plurality of focusing lenses of the same type or a plurality of focusing lenses of different types, to suit various environments in which the present invention is embodied.

[0056] Furthermore, the present invention is not limited to the illustrated example, and various modifications and variations are possible, such as further including a concave lens and / or a convex lens in the optical path between the focusing lens 150 and the material 1 in some cases.

[0057] 3 shows cross sections of the focused laser spots of first laser A and second laser B irradiated onto material 1. The beam width (cross section) of second laser B for heating by-products at the site where material 1 is cut is larger than the beam width (cross section) of first laser A for cutting material 1. Preferably, first laser A and second laser B, which share a single optical path, can be formed coaxially as shown in FIG.

[0058] The light width of each of the first laser A and the second laser B may be determined solely by the light width when emitted from the first laser light source 110 and the second laser light source 120, but in some cases, the light width can be adjusted by providing an aperture, lens, etc. on the single light path of each of the first laser A and the second laser B.

[0059] In this regard, FIG. 2 shows a case where an aperture 160 is provided on a single optical path of the second laser B, and the optical width of the second laser B is adjusted by the width of the opening of the aperture 160.

[0060] FIG. 4 shows a case where the pulses of the first laser A and the second laser B of the laser cutting device 100 of FIG. 2 are provided in synchronization with each other.

[0061] More specifically, Figure 4(a) is a graph showing the pulse of the first laser A over time t, Figure 4(b) is a graph showing the pulse of the second laser B over time t, and Figure 4(c) is a graph showing the pulse of the first laser A and the second laser B combined over time t. In Figures 4(a) to 4(c), the x-axis represents time t and the y-axis represents amplitude. The duration of the pulse of the second laser B is longer than the duration of the pulse of the first laser A.

[0062] As previously described in FIG. 2, the pulse duration of the first laser A is, for example, picoseconds (ps, 10 -12 s) or femtoseconds (fs, 10 -15 The duration of the pulse of the second laser B may be in nanoseconds (ns, 10 -9 s) units.

[0063] As described above, the pulse synchronization unit 130 delays and synchronizes the first laser A and second laser B emitted from the first laser light source 110 and the second laser light source 120, respectively, and then inputs a pulse width modulation signal PWM to each of the first laser A and second laser B. This makes it possible to obtain first laser A and second laser B pulses that are synchronized with each other, as shown in FIG.

[0064] FIG. 5 shows a schematic diagram of a laser cutting apparatus according to another embodiment of the present invention.

[0065] The laser cutting apparatus 100' of Figure 5 is a modified version of the laser cutting apparatus 100 of Figure 2, and may further include a mirror 170 between each of the first laser light source 110 and / or the second laser light source 120 and the optical splitter 140 for adjusting (changing) the optical path of the first laser A and / or the second laser B.

[0066] As described above, in order for the second laser B to pass through the optical splitter 140, the second laser B entering the optical splitter 140 and the second laser B exiting the optical splitter 140 must form a 180-degree angle (i.e., a straight line). On the other hand, in order for the first laser A to be reflected by the optical splitter 140 and for it to share a single optical path with the second laser B, the first laser A entering the optical splitter 140 and the first laser A exiting the optical splitter 140 must form a 90-degree angle (i.e., a right angle).

[0067] If the first laser light source 110 and / or the second laser light source 120 are not located on an extension line of the optical path incident on the optical splitter 140, it is necessary to change the optical path incident on the optical splitter 140. Therefore, a mirror or the like for changing the optical path may be included between the optical path between the first laser light source 110 and the optical splitter 140 and / or the optical path between the second laser light source 120 and the optical splitter 140, if necessary.

[0068] 5 shows, as an example, a case where the second laser light source 120 is not located on an extension of the optical path incident on the optical splitter 140, and therefore includes a mirror 170 for changing the path of the second laser B emitted from the second laser light source 120. However, the present invention is not limited to that shown in FIG. 2 and can be applied with various modifications and alterations when the first laser light source 110 and / or the second laser light source 120 are not located on an extension of the optical path incident on the optical splitter 140 as described above.

[0069] FIG. 6 shows a schematic diagram of a laser cutting apparatus according to yet another embodiment of the present invention.

[0070] The laser cutting device 100'' in FIG. 6 is a partial modification of the laser cutting device 100 in FIG. 2, and includes a cube-type optical splitter 140' instead of the planar optical splitter 140. In FIG.

[0071] The cube-type optical splitter 140' differs only in part in shape from the planar optical splitter 140, but its principle is the same as that of the planar optical splitter 140. Therefore, for an explanation of the optical path along which the first laser A and the second laser B emitted from the first laser light source 110 and the second laser light source 120, respectively, are combined by the cube-type optical splitter 140' and travel to the focusing lens 150, please refer to the explanations given above in Figure 2 and its modified version, Figure 3.

[0072] The description of the remaining components in FIG. 6 overlaps with that described above with reference to FIG. 2, and therefore reference is made to FIG.

[0073] According to this embodiment of the present invention, in the cutting process of secondary battery material, the material is heated by a heating laser (second laser B) to increase the reactivity (electronic reactivity, etc.) of the material, and by-products generated during cutting are heated and removed. This has the advantage of enabling clean processing of the cut area (such as the boundary area of ​​the cut surface). This significantly improves the quality of the manufactured electrodes and / or separators, thereby improving the performance of the manufactured batteries.

[0074] In the embodiments of the present invention, terms indicating directions such as front, back, left, right, up and down are used, but these terms are merely for convenience of explanation and may change depending on the position of the object of interest, the position of the observer, etc.

[0075] The electrode manufactured by applying the control method of the electrode manufacturing apparatus according to the embodiment of the present invention may be included in a secondary battery, and a plurality of such secondary batteries may be assembled to form a battery module. The battery module may be equipped with various control and protection systems, such as a Battery Management System (BMS) and a cooling system, to form a battery pack.

[0076] The secondary battery, battery module, or battery pack can be applied to various devices, specifically, but not limited to, transportation means such as electric bicycles, electric vehicles, and hybrids, and ESS (Energy Storage Systems).

[0077] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0078] A: First laser B: Second laser 100, 100', 100'': Laser cutting equipment 110: First laser light source 120: Second laser light source 130: Pulse synchronization unit 140, 140': Optical splitter 150: focusing lens 160:Aperture 170: Mirror

Claims

1. In an apparatus for cutting secondary battery materials with a laser, a first laser light source that emits a first laser for cutting the secondary battery material; a second laser light source that emits a second laser to heat the portion of the material to be cut; A laser cutting device, wherein the first laser and the second laser are synchronized and irradiated onto the material with a single optical path.

2. The laser cutting device according to claim 1 , wherein the second laser heats the material to increase the reactivity of the material and remove by-products generated during the cutting.

3. the first laser has an ultraviolet band; the second laser has an infrared band; The laser cutting device according to claim 1 or 2, wherein the output of the second laser is smaller than the output of the first laser.

4. 4. The laser cutting apparatus of claim 3, wherein the duration of the pulse of the second laser is longer than the duration of the pulse of the first laser.

5. The duration of the pulse of the first laser is from a few picoseconds to thousands of picoseconds (ps, 10 －１２ s) or a few femtoseconds to thousands of femtoseconds (fs, 10 －１５ s), The duration of the pulse of the second laser is from a few nanoseconds to a few thousand nanoseconds (ns, 10 －９ 5. The laser cutting device of claim 4, wherein the value of

6. 3. The laser cutting device according to claim 1, wherein the first laser and the second laser are coaxially irradiated onto the material, and the beam width of the second laser is larger than the beam width of the first laser.

7. further comprising a pulse synchronization unit coupled to the first laser light source and the second laser light source, respectively; 3. The laser cutting device according to claim 1, wherein the pulse synchronization unit synchronizes the first laser and the second laser emitted from the first laser light source and the second laser light source, respectively, to perform pulse width modulation (PWM).

8. an optical splitter that combines the first laser and the second laser emitted from the first laser light source and the second laser light source, respectively, on one optical path; The laser cutting device according to claim 1 or 2, wherein the combined first laser and second laser are irradiated onto the material.

9. The laser cutting device of claim 8 , wherein the optical splitter reflects the first laser and transmits the second laser.

10. the angle between the first laser entering the optical splitter and the first laser exiting the optical splitter is 90 degrees; 9. The laser cutting apparatus of claim 8, wherein the angle between the second laser entering the light splitter and the second laser exiting the light splitter is 180 degrees.

11. The laser cutting device according to claim 8 , wherein the optical splitter is a planar optical splitter or a cube optical splitter.

12. 12. The laser cutting device of claim 11, wherein the planar optical splitter is a mirror that reflects the first laser and transmits the second laser.

13. further comprising a focusing lens disposed in a light path between the light splitter and the material; The laser cutting device according to claim 8 , wherein the focusing lens converges the first laser and the second laser and focuses and irradiates the first laser and the second laser onto the material.

14. 14. The laser cutting apparatus of claim 13, wherein the focusing lens is provided in at least one form and includes a planar convex lens, a double-convex lens, or a meniscus convex lens.

15. The laser cutting device according to claim 1 or 2, further comprising an aperture for adjusting a beam width of the second laser.

16. further comprising a mirror disposed between the first laser light source and the optical splitter; The laser cutting device of claim 8 , wherein the mirror adjusts the optical path of the first laser beam incident on the optical splitter.

17. further comprising a mirror disposed between the second laser light source and the optical splitter; The laser cutting device of claim 8 , wherein the mirror adjusts the optical path of the second laser beam incident on the optical splitter.

18. The laser cutting device according to claim 1 or 2, wherein the secondary battery material includes at least one of a positive electrode, a negative electrode, and a separator of a secondary battery.

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